Propellant distributor for a thruster

Abstract

A propellant distributor or anode includes a plenum chamber and a plurality of outlets. The at least one plenum chamber is configured to receive a flow of propellant from an inlet, and the plurality of outlets are configured to distribute the flow of propellant into an inner channel wall and an outer channel wall of a discharge channel.

The invention claimed is: 
     
       1. An apparatus, comprising:
 a thruster discharge channel in fluid communication with a propellant inlet, the propellant inlet configured to receive a flow of propellant; and 
 a propellant distributor disposed within the thruster discharge channel, the propellant distributor comprising: 
 a plurality of inner surfaces defining a plenum chamber such that the entirety of the plenum chamber is contained within the propellant distributor and downstream from the propellant inlet; 
 a splitter section disposed completely upstream of the plenum chamber, wherein the splitter section is separate from the plenum chamber, wherein the flow of propellant enters the plenum chamber via the propellant inlet, wherein the plenum chamber includes a post-plenum orifice extending to the splitter section such that at least some of the flow of propellant exits the plenum chamber and enters the splitter section via the post-plenum orifice, wherein the splitter section is configured to divide the flow of propellant into separate flows traveling in different directions within the thruster discharge channel; and 
 a plurality of outlets extending from the splitter section, wherein each one of the plurality of outlets are located upstream of entireties of the plurality of inner surfaces defining the plenum chamber and downstream of the propellant inlet, wherein each one of the plurality of outlets are configured to distribute the flow of propellant to a plasma of the thruster discharge channel. 
 
     
     
       2. The apparatus of  claim 1 , wherein the propellant distributor is configured to shield the plurality of outlets from debris or plasma. 
     
     
       3. The apparatus of  claim 1 , wherein the propellant distributor is configured to evenly distribute the flow of propellant into the thruster discharge channel. 
     
     
       4. The apparatus of  claim 1 , wherein the propellant distributor comprises a downstream external surface having chamfered edges configured to prevent electric field concentration. 
     
     
       5. The apparatus of  claim 1 , wherein the post-plenum orifice is offset from a radial center of the plenum chamber to balance the flow of propellant between a first flow towards an inner channel wall of the thruster discharge channel and a second flow towards an outer channel wall of the thruster discharge channel. 
     
     
       6. The apparatus of  claim 5 , wherein the splitter section is configured to discharge the first and second flows through the plurality of outlets. 
     
     
       7. The apparatus of  claim 1 , wherein entireties of each one of the plurality of outlets are located upstream of the plurality of inner surfaces. 
     
     
       8. The apparatus of  claim 1 , wherein the post-plenum orifice includes a first section extending from the first one of the plurality of inner surfaces and a second section extending between the first section and the splitter section, wherein the second section has a greater cross-sectional area than the first section. 
     
     
       9. The apparatus of  claim 1 , wherein the propellant distributor comprises sidewalls and a downstream portion, the downstream portion having a downstream external surface facing an ionization region contained in the thruster discharge channel, wherein each of the plurality of outlets are located on the sidewalls and extend substantially perpendicular to the propellant inlet. 
     
     
       10. The apparatus of  claim 9 , wherein the propellant distributor comprises a first overhanging section disposed downstream of the plurality of outlets, the first overhanging section extending from the downstream portion. 
     
     
       11. The apparatus of  claim 10 , wherein the propellant distributor comprises a second overhanging section disposed upstream of the first overhanging section and downstream of the plurality of outlets.